What Are the Most Polluted Cities in the World?

Most large cities in the developing world are breaching global air pollution guidelines, according to new data from the World Health Organization.

According to an article at the World Economic Forum, air pollution has risen by 8% globally in the past five years, with the WHO estimating that it causes 3 million premature deaths a year, making it one of the greatest environmental risks to human health.

The latest urban air quality data, collected between 2011 and 2015, reveals that 98% of cities with over 100,000 inhabitants in low- and middle-income countries do not meet WHO air quality guidelines.

Of the 3,000 cities in the WHO’s air quality database, the most polluted at the time of measurement was Onitsha, a fast-growing city in Nigeria, which recorded roughly 30 times more than the WHO’s recommended levels of PM10 particles. Peshawar in Pakistan was in second place, followed by Zabol in Iran.

Four of the 20 urban areas with the worst air quality at the time of measurement were in Nigeria, three were in Saudi Arabia, three were in India, and two in Iran.

Despite the bad news, the data also revealed that more than half of the monitored cities in high-income countries and more than one-third in low and middle-income countries reduced their air pollution levels by more than 5% in five years.